Retract mechanism



3 1970 w. K. SCHIMMEYER RETRACT MECHANISM Filed April 11, 1968 R V M w M T NQ Wm M mg mum W f/ m S\ K o W n United States Patent US. Cl. 891.811 5 Claims ABSTRACT OF THE DISCLOSURE A retract mechanism for pulling a missle umbilical connector away from the missile and into the body of the missile launcher frame during missile launch wherein as the missile moves away from the launch mechanism, a device (not part of the instant invention) exerts a force on the missile umbilical connector to move the connector away from the missile and partially into the body of the missile launcher frame. This initial force causes a piston, which is connected to the umbilical connector internally of the missile launcher frame, to uncover a fluid pressure inlet, whereby the fluid pressure entering a cylinder forces the piston and connector to move further into the missile launcher frame at which point the piston is latched in place.

Background of the invention This invention relates generally to retract mechanisms and more particularly to a retract mechanism suitable for umbilical connections.

In the launching of missiles and rockets it is often necessary to feed electrical and fluid (conduits into the vehicle through an umbilical connector which is generally located on the launch mechanism frame. It has been found desirable to retract the umbilical connector away from the missile as soon as possible in order to protect the connector from damage either during missile blast-off or thereafter. The retract mechanism must actuate by an independent positive force with a high degree of reliability. Prior art devices have been utilized with varying degrees of success. Such prior art devices have consisted essentially of hand operated devices and mechanisms which depend upon the power system of the launch platform, such as a ship or submarine. These devices are generally slow and unreliable and have not been entirely satisfactory.

Summary of the invention Accordingly, one object of this invention is to provide a new and improved piston operated retract mechanism.

Another object of the invention is the provision of a new and improved piston-cylinder retract mechanism which is responsive to a small mechanical force.

Still another object of the present invention is to provide a new and improved piston-cylinder retract mechanism which is actuated by an independent positive force initiated by a small mechanical movement.

A still further object of this invention is the provision of a new and improved piston-cylinder retract mechanism which is capable of rotational movement with respect to a support.

Another still further object of the instant invention is the provision of a new and improved piston-cylinder retract mechanism which is unidirectional and latches the piston in the retracted position.

One other object of this invention is the provision of a new and improved piston-cylinder retract mechanism for a missile umbilical connector which completely retracts the connector into a safe position in response to a small mechanical force.

Briefly, in accordance with one embodiment of this invention, these and other objects are obtained by a piston 3,490,331 Patented Jan. 20, 1970 having an axial extension on one end thereof protruding through an aperture in a closed end wall of a cylinder in which the piston is slideably mounted. A pair of axially spaced sealing members each extend about the circumference of the piston between the piston and the cylinder, and a pressure supply inlet located through the sidewall of the cylinder communicates with the piston between the sealing members such that a small movement of the piston causes one of the sealing members to cross over the pressure inlet enabling the pressure source to push the piston out of the cylinder thus retracting the piston extension.

Brief description of the drawing of the retract mechanism according to the present invention.

Description of the preferred embodiment Referring now to the drawing, wherein like reference characters designate identical or corresponding parts, a cylinder casing 10 having an open end 12 and an end wall 14 with an aperture 16 defined within the closed end wall is shown as pivotally mounted in a bearing 18 to form a ball joint with a support 20' to provide the cylinder casing 10 with a freedom of rotational movement with respect to the support 20 while axially constraining the cylinder relative to the support. A cylindrically shaped piston 22 is slideably mounted within cylinder 10 and has an axial extension'24 integrally formed therewith protruding through aperture 16. A pair of axially spaced sealing members such as O-rings 26 extend about the circumference of the piston 22 within recesses formed therein to form a seal between the piston and cylinder walls. An elongate cavity 28 is formed within the piston extension 24, and is sealed at the outer end thereof by a rod 30 fitted therein. A pair of apertures 46 and 48 are provided in rod 30 and are spaced from each other a distance greater than the thickness of cylinder wall 14 for reasons explained hereinafter. An umbilical connector 32 is secured to the forward end 34 of rod 30 for connecting electrical and/or fluid conduits to a missile or rocket prior to launch. The umbilical connector 32 extends through an aperture 36 in a launch mechanism frame 38, and after being disconnected from the missile (not shown) it is desired to retract the umbilical connector 32 through aperture 36 into the missile launch mechanism frame 38.

A conventional independent mechanism not shown, nor forming part of the present invention, may be utilized to uncam the umbilical plug connector 32 from the missile receptable and push the connector through a small distance toward frame 38 away from the missile. Since the piston 22, extension 24, rod 30 and umbilical connector 32 are all integral, axial movement of the connector toward the cylinder wall 14 will cause the O-ring 26 nearest to wall 14 to move toward open end 12 of cylinder 10. An inlet 40 is provided through a sidewall 42 of cylinder 10 to supply a fluid under pressure against piston 22. In the position shown in the drawing, the O-rings 26, being on either opposite side of pressure inlet 40, equalize the forces exerted on the piston 22 such that no movement results. Should one of the O-rings 26 leak, the fluid pressure supplied through inlet 40 will either escape through open end 12 of cylinder 10 or will enter cylinder chamber section 44 pass into an aperture 46 to cavity 28 and exit through an aperture 48 externally of the cylinder. Thus, it is seen that should one or both of O-rings 26 develop a leak the pressure supplied through inlet 40 will not cause axial movement of piston 22 Within cylinder 10. However, as the umbilical connector 32 is moved toward the cylinder by the umbilical connector disconnect mechanism (not shown) the O-ring nearest end wall 14 of cylinder 10 will pass by pressure inlet 40, and aperture 48 will move inside of cylinder 10, such that pressure will be exerted against a back wall 50 of piston 22 to quickly and positively move the piston 22 through open end 12 of cylinder 10. Thus, it is seen that in response to a small mechanical force the piston will be quickly retracted.

Piston 22 has a cavity 54 formed therein with an open end 52. As the piston 22 moves through opening 12 of cylinder 10, in response to pressure entering chamber 44, the piston cavity 54 will be forced to envelope a conformingly shaped guide members 56 which is attached to support 20 by means of a support structure 58. The piston movement will be terminated when the forward extremity 60 of piston 22 engages a wall 62 on support structure 58. A circumferential groove 64 formed in piston 22 near the forward extremity 60 will be engaged by a latch mechanism 66 when edge wall 60 has engaged support wall 62. The latch 66 will hold piston 22 against wall 62 by biasing means such as coil spring 68. In the totally retracted position with forward extremity 60 abutting against support wall 62 and the latch 66 in engagement in groove 64, the umbilical connector 32 will be com pletely retracted within the missile launch frame 38. The latch 66 limits the piston to unidirectional movement by preventing the piston and connector from returning to the extended position.

Obviously, numerous modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A retract mechanism comprising an elongate casing having an apertured end wall,

a slideable member disposed in said casing in an initial position,

fluid pressure input means formed on said casing,

a plurality of fluid sealing means on said slideable member and located on opposite sides of said fluid pressure input means when said member is in its initial position,

an elongate extension formed on said slideable member and protruding beyond said apertured end wall when said member is in its initial position,

a cavity formed in said extension having a plurality of apertures in Communication therewith, at least one of said apertures being in communication with a chamber formed by said casing and at least one other of said apertures being outside of said casing when said slide-able member is in its initial position thereby to preclude inadvertent movement of said slidea-ble member by fluid pressure entering said casing chamber, all of said apertures being in communication with said casing chamber upon a predetermined movement of said member within said casing by an external force applied to said extension thereby to effect rapid expulsion of said member from said casing by fluid pressure entering said casing chamber.

2. A retract mechanism comprising a casing having a side wall, an unrestricted open end and a closed end with an aperture defined within said closed end,

a piston slideably mounted within said casing for movement between a first position and a second position, and having an axial extension on one end thereof for protruding through said aperture in said closed end of said casing,

a plurality of axially spaced sealing members extending about the circumference of said piston between said piston and said casing, and

means for supplying pressure through said side wall of said cylinder between said sealing members when said piston is in said first position and between said one end of said piston and said closed end of said casing when said piston is in said second position.

3. The mechanism of claim 2 wherein said piston extension has a cavity defined therein of axial extent greater than the thickness of said closed end of said casing, and

a pair of axially spaced radially extending apertures defined in said piston extension each in communication with an opposite end of said cavity.

4. The mechanism of claim 3 further comprising a support for said casing, and

bearing means between said cylinder and said support for providing a ball joint therebetween.

- 5. The mechanism of claim 4 further comprising means for latching said piston in said second position.

References Cited UNITED STATES PATENTS 2,604,076 7/ 1952 Treavaskis 92-110 X 2,996,046 8/1961 Skopp et a1. 26.1 X 3,011,451 12/1961 Grifiin 89-7 X 3,331,278 7/1967 Brown 891 SAMUEL W. ENGLE, Primary Examiner U-$-. C -R= 91-410 

